Steam-generator.



G. S. DRUMMOND STEAM GENERATOR.

APPLICATION FILED 1111111s,1910.

Patented N0v.14, 1911.

2 BKEETS-SHEET 1.

G. S. DRUMMOND.

STEAM. GENERATOR.

v' APPLICATION FILED JUNE 3, 1910.

2 SHEETSSHEET 2.

Patented Nov. 14

cnARLEs.snvcnamfnnumiuoivn, or Lonno-N, ENG-LAND.

STEAM-GENERATOR.

Specification of LettersPate'nt. P t ted Nv.- 14, 1911.

. Applicatioufiled June 3, 191d. Serial No. 564,779.

To all t vho'm it concern:

Be itknownthat L CHa'nnns SINCLAIR DRUMMOND, subjectof the King of-.Great Britain, residing at 87 -89- Aldgate, London,

England, have invented new and useful Improvements in Steam-Generators, of-which the following is a specification.

This'invention relates tofa tubulous steam generator which embodies new features and new combinationsof features whereby an.

extremely highrate of heat transmission to the water is obtained under conditions which provide great safety and durability;

According to this invention, the tubes exposed to the direct heat of. the fireare f small bore and formed with thick walls, the section of the metal of the tubes being -for"exa mple .about three times that of the bore. These tubes are fed with water at their lower ends, and at their upper ends constricted passages are provided for the escape of the heated'fiuid to the steam space of the boiler, the resistance to escape being within the tube, will enable thewater flowsuch that the water inthe thick tubes, direct-lyexposed to the fire, isunder considerable 1 super-pressure and attains a corre; sponding super-heat,.-the'formation of steam being suppressed -until: the water escapes through the constricted passages. The very high rate of heat transmission which results.

from" the employment of such an arrangement and -proportionslis:partly due to the" nature and arrangenient of the heat supply which "consists of highly superheated vapor.

The hightefiiperatureiof the source of heat in conjunction with the exceptionally' high temperature of the exterior surfacevof'tlie metal of the tubes is such as to preclude dis sociation of' the-vapor anddepositionfiiof'i. carbon or solid compounds thereof; onthe outside of the tubes, permitting-the tnbesto be completely immersed;- in the flames 10f. superheated vapotwitlitiht' interferingwith its complete. combustion? The heat'thus received atfga very rapid rate, conducted I jtaken along the line 33 of Fig. 1.' Fig. 4;

partly in a radial direction andipartlyalong the wall. of the; ube to theiiinerlsurfa'ce thereof, causing he-aupperz ;portion of; th inner surface to b wellf supplied'iwith heat as the lower portion. {-;This, coupled with the suppression. of 'steamfgeneration ing therein to absorb heat at an unprecedented rate. 4

The use' o f:thick-walled tubes in so-called 'largedf-scale of one of a plurality of 'ers of gaseous fuel, and Figs. 6 and/7 show representative sections of the thick walled tubes which are exposed to the direct flash boilers, iswell known, but in such boilers the function of the thick wall is to serve as areservoir of heat, as a substitute for a reservoir of steam anda reservoir of heat of a mass of boiling water which is provided in other boilers.

The function of the thick wall in the tubes capes through the constricted passages into the steam space under the influence ,ofthe considerable superpressure, steam is generp-r'essure becomes. relaxed and the energy of expansion due to the fall from the superpres sure, breaks up the stream of unevapoing suspended in an'atmohere of steam. The very fine spray will impinge with con- ,atedat the expense of the superheat as the a siderable velocity on' the higher situated tubular heating surfaces, and by maintaining them in a wet condition, raise the rate 'ofheat transmission much above that which is normally attainable. So much energy v'vill be available from the descent from the super-pressure that the agitation will 'cont-lnue after the evaporation has been completed, and thus the superheating of the 'steam will be' promoted.

The invention above described may be embodied in a tub ulous boiler constructed as --will be described with reference to'the acjcompanyingdrawings, in which Figure, 1' is a s1de'"sectional elevation.

Fig 2 is a. part sectional plan, taken along the-,,line- 2 -'2, the feed heating coils being omitted. .Fig. 3 is apart sectional plan,

is apart sectional plan, taken along the line heat of the fire. Fig.8 shows, a'inodification series of excursions across the furnace, the

formed'witha plurality of loops. To this coil the water is admitted at a and after a partially heated water is delivered at'a to i a tube 6 of relatively large diameter, outside tube 6 is shown built up of a number of short sections united by nipple tubes 6 but it may be formed integrally. From the tube b, which is common to a plurality of like sections of which the boiler is composed, a

. downtake p'pe 03 leads to a junction-piece 6 so formed as to receive, in a fluid-tight man- I a ner, the ends of two bent thick-walled'tubes f the ends of the upper branches'of which are secured to ajunction-piece 9. To this is secured a T shaped connection h from which tubes. 6 i curved to, allow for expansion lead in opposite directions to the ends of a tube 0 which is built-up of sections connected 'by nipples 0 according to the method of cone- 'struction of the tube 6 previously described.

7 The'fexit of the'fluid from the tubes 2': i?

into 0 is commanded by non-return valves y j. From a the fluid, which will consist of atomized water suspended in an atmosphere of steam, will flow upward through short.

tubes m to a composite horizontal tube it during which the suspended atomized water will be converted into'steam' and flow past a non-return valve 0 into atube 0 which is common to all thesections of the boiler. The

tube 0 is also shown as built up ofisec tions though, being outside the furnace, it may be I. integrally made. From the tube 0 the steam, 40.

assembled from'all the sections of the boiler,

' is led through the pipe p to flow in parallel through the tubes 9 g of the super-heating portion of the steam generator to the pipe 1" whereby. it is conducted away for useful ipes (1, each being provided-witha blow-o cock d v are, beyond the blow-01f cocks, interconnected by a; pipe 5, having at one end a blowofi' cock Ls? and at the other end a cook 8 through which, under special circumstance of-emergency, feed water can be admitted from the feed-pump. Perforated bathe-- plates 25, as shown in Figs. 1 and 2 may be fitted to'hinder the upward flow of the products of combustion-- and distribute them thesteam generator is controlled by means cock d [of turn-cocks d and,.by the aid of a single glass-gage, means are provided for ascertaining the level of the .water in each of the For this pur pose, in each section of the boiler, a pipe leads from the down-take pipe (1 past a stopto a tube k common-to all the sec-,

ition takes place with a tions of the boiler. Correspondingly, in

- d .and 12, of any section are opened and those of the other sections closed, the level of the water inthe open section will be indicated by'the water level in the glass-gage, and by appropriate adjustment of the feed cocks d the water in all the sections of the boiler can be regulated to a uniform level.

' The junction-piece g, to which twotube's f are connected, has only one branch of small section in the stem of the T piece it -whereby the superheated fluid can flow to the tubes i i. From this constricted section the fluid escapes: in equal quantities in opposite directions, and'after passing the non-return valves 7' j the streamsare reversed in direction and meet one'another with a violent eddying. motion'within the tube 0.

The non-return valves '7' 7' will serve to prevent the back flow of steam into the tubes i 2'? f in the event of excess pressure in any oiie of the sections.

Fig. 6 shows a section of a cylindrical thick-walled tube of small bore of which the proportions are such that the character and rate of heat transmission will be that above described. A tube with a bore of one-' quarter of an inch diameter and a wall one eighth of an ,inch thick for example, will effect the desired purpose.

Fig. 7 shows a tube of modified section in which the thickness of the wall is the same as in Fig. 6, and also the sectional area of the bore," moreover the dimension, of thetube is'equal to that of the round tube in Fig. 6, thereby leaving the like width of air spaces between thetubes. The tube in plan,

. of Fig. 7 will be derived by taking a round 1 I tube of larger bore and flattening it as shown, the ends of the tubes where connection with the junction pieces is effected beleft round.

%he burner to is fed with combustible fluid as follows :Liquid fuel, under a con siderable. air pressure, is supplied to an upward sloping pipe 00 of small bore situated above the flames of the burner, the pipe is continued downward'and again upward,'re

- quiring the fluid to'undergoa triple excursion exposed to the heat of the flames of the burner. It then escapes at a very high velocitythrough theadjustable nozzle y into the interior of the burner to entraining therewith a quantity of air. The upward slope of the. pi e w permits of a relatively large surface 0 liquid from which evaporadi'sturba'nce of the liquid. Thus little or no minimum degree of relatively high temperature of the outer surfaces of the'thick Walls of the tubes f will prevent the deposition of soot on the tubes:

Instead of tli ere being three excursions of the combustible fluid through the flames of the burner, the number may be more or less, to correspond withthe less or greater volatility'of-theliquid fuel which is supplied.

In-Figs 8-is shown an automatic" regulator oil-the feed-water which may be employed as an alternative to the; handregulation "method of distributing thev feed water.

among the several sections of the boiler or asan addition thereto. lhis operates-by means of a thermostat which consists of a rod z extending along the axis of the tube 0 and composed of a metal which has a higher co-eflicient of expansion than that of the metal of the tube a. This rod extends fromthe tube onearly to the tube 72 being thereat inclosed within a branch 03 of the down-take pipe d. The passage between I) -ity of the stem of aremovable plug 72 The axis of the tube '0 and contained rod .2 is

situated at about the normal level of the water in the boiler when quiescent. One end of therod z is securedto'a socket 2 at the front of the-boiler whereby the action of the thermostat can be adjusted.

Iclaim: v 1. In a tubulous steam generator, means for suppressing the generation of steam in the tubes exposed to the radiant heat of the fire and for s'uperheating the water flowing therein, comprising a constricted sectional area of escape from the said tubes at-the upper ends thereof. i s

2. In a tubulous steam generator, means for suppressing the generation of steam in the tubes exposed to the radiant heat of the fire and forsuperheating the water flowing therein, comprising a constricted sectional area of escape from the said tubes at the upper ends thereof, the. said tubes having such a transverse section that, that of the wall exceedsthat of the waterspace thereof. 3. A steam generatorjconsisting of a plurality of sections .of which each comprises.

a tube of small borevhaving a relatively thick wall which-isexposed to the direct heat of the tire, a tube of larger bore sit- -the boiler.

uated away from the direct .heat of the fire and a constricted passage connectmg the said tubes, combined with means for stipplyin watertothe lower end of the'thickwalled tube at such a rate that'the generation of steam within that tube is suppressed by the super-elevation of pressure therein.

4. A. steam generator consisting of a plu-l rality ,of'sections .of which each comprises a tube of small bore having a relatively thick wall which is exposed to the direct heat of the fire, and a tube of larger bore situated away from the direct heat of the fire, a constricted passage connecting the said tubes-and a non-return-valve situated beyond the constriction, combined with means for supplying water to the lower end of the'thick-walled tube at such a rate that the generation of steam 'within that tube is suppressed by the super-elevation of pressure therein.

5. A'steam generator consisting of a plurality of sections of which each comprises a tube of small bore having a relatively thick wall which is exposed to the direct heat of the fire, a tube of larger bore situated away from the direct heat of the fire, and a constricted passage connecting the said tubes, combined with means for supplying water to the lower end of the thick-walled tube at such a rate that the generation of steam-within that tube is suppressed by the super-elevation of pressure therein, and with means for. individu .ally regulatingthe supply to each sectionof the boiler.

. 6. A steam generator consisting of a plurality of sections of which each comprises a tube of small bore having a relatively thick wall which is exposed to the direct heat of the fire, a'tube of larger bore sitfuated away from the direct heat of the fire and a constricted passage connecting .the-

-ply to each section and with means tor observing -the water level in each section of 7. Asteam generator consistingof aiplurality of sections of which each comprises a tube of small bore having a relatively thick wall which is exposed to the direct heat of the fire, a tube-of larger'bore sit uated away from the'direct heat of the fire, and a constricted passage connecting the said tubes, combined with means for supplying water to the lower end of-the thickwalled tube at such arate that the generaply to each section and'a gage-glass'cominon the furnace to which the 'pre-heated water is conducted, and a plurality of tubular sections each connected with the said chamber. by a passage of controllable section through.

which the fluid flows in parallel without intermixing until it reaches the condition of steam, said tubular sections consisting, in

the ortion exposed to-the direct heat of the E v I walls and having such constrictions at the. upper ends of such portions as to suppress the generation of steam bya super-elevation of pressure. I Y

-In testimony whereof I have signedimy 9 name" to this specification in the presence of. two subscribing witnesses.

CHARLES 'snwnua DRUMMONIL. Witnesses:

.H. W; WAGIioRN, H. D. Jamison.-

f tubes of small bore and thi 15 

